After 1950, Chevrolet switched from Carter to Rochester. Carter made carburetors to replace the Rochester (aftermarket or OTC). Whether a Rochester or a Carter, both are 50+ years old and both are subject to significant wear. This is where a professional restorer is needed if you want a well behaved carburetor. Carburetor rebuild kits are for carburetors that have little wear. Many choose to find a carburetor, install a rebuild kit and fingers crossed that the wear is not too bad (works good enough). Right now we are at the crossroads of experimenting with EFI kits. They have not yet be proven reliable (it takes many years to find out).
In 1960, GM started using the low profile carburetor air horn design on trucks. It requires a center bolt to hold the air cleaner to the carburetor. Previous designs used a clamp to compress around the carburetor throat. In 1960, Carter also switched to the center bolt design.
If you go by the Carter recommendation (attachment) you would purchase a YF 3211s but this is an automatic choke carburetor. I like the YF 2100s manual choke but beware it is made for the older style air cleaner.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
